Engine crank case construction



F. G. HOBART ENGINE CRANK CASE CONSTRUCTION Aug. 20, 1935.

Filed April 25, 1932 4 Sheets-Sheet l Gttorneg Aug. 20, 1935. F. G. HOBART 2,012,009 ENGINE CRANK CASE CONSTRUQTION Filed April 25, 1952 4 Sheets-sheaf 2 3nnentor G ttorneg Aug. 20, 1935. F. G. HOBART 2,012,009

' ENGINE CRANK CASE CONSTRUCTION Filed April '25, 1932 4 Sheets-Sheet 3 Snnentor (Ittrneg Aug. 2 0, 1935. F. G. HOBART v "Hm ENGINE CRANK CASE CONSTRUCTION Filed April 25, 1932 4 Sheets-Sheet 4 48 Snventor W (Ittorneg Patented Aug. 20, 1935 u siren s m ss V -2,o12;009 k v ENGINE :GRANKnCASEiGD NSXTRUGTION FranklinGJHobart;Bel0it,Wis.,iassignor to'Fair "bankS,"Morse -&"Go., Chicago; 111., a corporation 1 of Illinois Application. April :25, 1932, Seria l' N0.607,308 -11" Claims. (613184-513) ,This, invention'relates ".170 improvements, a in en- .gine crankcase construction, 1 and more particularly to=an improvedi'arrangementfor lubricating main engine bearings, :preventingleakage of oil, zand :returning collected oil splash. to' a bodyof lubricantlwithin the .enginevcrankcase.

:Anobject of the present.invention'isxto-provide an improved engine base or crankcase,- consisting, in thGYPIGfGII'Bd embodiment, of azlower portion or; :oil reservoir a part of which forms; thellower halves 1 :of the :main' bearings, to the :baserbeing assembled, axbearing cap, and azzcrankcasergcover :which, when; assembled, willhcoactzto constitute a novel arrangement/of ,oiling: and oilereturn :passagesfor lubricating thermain bearings of; anaen- 'gine.

.Aufurther objectis "to provide an improved crankcasestructure consisting of a lower case portion; a bearing cap ,and a crankcase cover which is neat and compact, and forms an oil-tightstruc- "ture when assembled. additional obj ect of the invention is attained i Lin improved and novel means for collecting lubricant elevated by splash and distributing such lubricant; bygravity, to bearings located out of the direct path' of splash or spray; V

V A still further object is attained in an improved arrangement for collecting and recirculating oil which may tend to be forced outwardly otengine shaft'beaiings, the arrangementalso providing, an ,oil seal precluding escape of gases "andioilvapors through'the'oil'return passages. v fFurther objects'jand advantages will appear from theiollowing detaileddescription of a pre- 0 "ferred embodiment oflthe invention, and from'the nac companyingvdrawings, inwhich: r (Fig. p11 ,is a vertical ,section, taken, en'dwise through a, portion of a crankcase designed: in accordance with the present invention; Fig; 2 i is. a

, vertical section along. line .2-I2 'of .Fig. 1 ;1-Fig'; '3i-is an enlarged 'crosslsection taken ,on' 1ine1'3--? 3 10f "Fig.1 ;"Fig. 4 'isa. top perspective view .ofa bearin cap; Fig. r 5; is ;a perspective View of the bearing cap cof Fig. 4, shown in) inverted position v liig. 6 is a sectional perspective view'oftthe:bearingporltion of? thelcrankcase, andrFig. 7 is axsectionalzpergspective viewvof aportion of the'crankcasecover, ":as viewedalong line-"l-el of'Fjg. 2.

.Referring' by numerals ofireferenceto the? drawings, t0 :.designates, =g-enerally,-p'aFpreferred type :of .ccrankcase. which 1 includes, by preference, a lrmrer case portion? l l ,1whichiservesiitoccarryrbearing caps l2; and a cover: t3. Therportion'i t I includes an: oil reservoir 6 ammo lower: halveslrticof walls; I 6. head I l ise peratiVelyiassociatedwith-the usual :panion surfaces liif,

tthemain ,crankshaftabearingst and outer wins 5 l6 .which-encasehand supporttthesassembly.

, "The engine chosen to illustrate an embodiment softthe, presentdnvention is of;- horizontal type -al- '-,tho.ugh certain of the-principles of construction -5 ,hereindescribed are;equallyrapplicable toengines of -.vertical/,type. i'Ihe cylindersand pistonfinot shown) may be of any suitable constructiongsuch e as: usually employed in gas engines, the vengineof --1 embodying ra cross-head J! 1 to ,which ,the no piston has preferably at-rigid connection,,-and crosshead; guides i=8 5 formed, .by preference, tintegrally withlthe.crank. case casting, which'also.connstitutes thej-lowerportions v I l together \with .the

qAsibest appears: from Fig. 1 1,. the. cross- I5 connecting rod I 9, engaging .the crankshaft '20; zwhileva single cylindereengine has :beenrchosen z=fors illustration, :a rnumber of principles herein disclosed are, as will :appear, equally .applicable .320

;to multiecylinder-engines, in which the crankshaft may "be provided -:with -:a plurality of cranks or i'throws instead of the single .throwe arrangement v-.-selected:for-sin' plicity of illustration. Theron-ank- '1 shaft 3 is:,.mounted i at .ornear; its opposite'enda; in $25 hearings, :indicated;gener;al1y atz I ,(Fig. 2), ,i the" arrangement and =.construction \of ..the bearings ibeinggby preference ,rthesame atlthe .oppositeends zasuviewed-toward the front ot the; engine or toward the: left in -Eig.:.1. Aliner of :bearing zmetalluiis 1 preferably mounted in anyv usual orssuitablelmanr235 :ner, within-the; casting constituting-,the:.casaporution II which isicharacterizedbythreeparallel, ssubstantiallyv horizontal-stepped :surfaces' 23, J24 aandliES.v -In :assembly, the horizontal surfaces 23 serve to receiveandcooperate-iwitlrsiniilaruoom (Eigstl,A=land5)-lonlthe under por-tioncof aeachupper-z bearing half-.91 cap, The rpurposez and: relation of ether-stepped z-surfaces s24 eand 2.25 will hereinafter xappear. :Riser ssurfaces xbetweenutheeadjacent steppedeportions; areiindll -;:oa ted respectively att=2 6"and 21 surfaces2'l being (provided withwa groovednoil-channelzn havinga averti'cahportionrextending downwardlyfrom-lthe surface 25 to'the plane of thewsurfaceszl, rand zthencessloping rangularly-rinto can eundercut 011 5 :receivingrand distributing duct 1 2-9, ;fa11..f (;)rha;pl11'- tposezmoreeclearly:hereinafter aappearing; rnt or zfneanthe outer! end ofzeachzof the bearing." :assem cbliesiiz l thererist formed by then-two bearing :halues,

annular 1 pill-receiving rrecess 30,:.'a portion of w which will appear in Fig. 6 and the location of which will best appearfrom Fig. 2. It will be understood that the opposite sides of each of the bearings is formed correspondingly to and symmetrically with the structure shown in Fig. 6, with the exception that surface is not continued on the side of each lower bearing half, opposite theone side shown in Fig. 6., r

Adapted to fit snugly between, so as to be engaged by the riser surfaces 26, is a corresponding plane lateral surface 3| of the upper bearing half (Figs. 4 and 5), and an adjacent surface 32 serving to engage the surface 24 and sub'stan tially vertical surfaces 33, mating with and abutting the surfaces 21 on the casting I I. The sur faces 33 are formed by the end faces of a pair of transverse rib portions 34 and 35 (Fig. 4) there being formed in the upper surface of rib 34,

lengthwise thereof and transverse to the bearing,

, a gasket groove 36. From the stepped construction of the upperjand\lower'bearing halves it will be noted 'thatalignrnent' of the mating bearing-member s and surfaces is permanently assured andyet adjustment permitted by the use of shims boltsjffollowedby selective removalof' such shims,

and againtakingup the cap screws or, bolts to' *reasseihblethe bearing halves in adjusted relation, according to prevailing practice. "also appearthat the upper bearing-halves are It will *provided withfa half annular cavity 30, forming continuation of the corresponding annular 'space within the lower bearing halves. hereinafter appears, the main bearings are continuously supplied with oil. Since an excess of oil may at times, be provided, certain of the oil 40.

thejrnainbearin'gs 21, along the crankshaft-20. Since the bearing membersare provided beyond the annular" recess '30; with shaft openings 31, provision is preferably made for preventingegress of oil, Qilyapor and 'fog through the openings 31. To this end I provide oil retaining rings 38, prefiiera'bly dimensionedto a size somewhatsmaller than the annular recess 30, in which each ring operates, so that, when the shaft 25 revolves, 'fanyoirwhichfinds'its way'along the shaft to this pointi will 'be arrested and thrown out by'the ring into the passage 30. Drain ducts are provided therefrom, as-indicated at 39, these being cored -inthe' castingll, so as toslope, slightly, toward the-central reservoir portion of the case, and eaemennmann m a vertical duct 40 leading; by preference, to thebottom of the oil reservoir l4. Arrangular innerend4l [of each duct i "40, serves todirect the returned oil into-the lowmay find itsway beyond the outer ends of portion of the oil reservoir. 1 The'-arrangement of oil return ducts just described, oifersa distinctadvantage in that by discharging'the returned oil at the lowermost portion 'of-the-case, the oil-in"any normal level in the-case, serves as a liquid seal, preventing ---'any egress-tr oil outwardly through the openfings 31,"such as mightoccur in the event'the ducts 39iopened directlyinto the case above the oil level therein. 7

It willappear thatfasthusfar describedythe structure- I1 1 including the lower portion of the crankcase, would present atop opening. The detachable cover I3 serving as 'a closure for such f 'opening, serves with the lower caseportiori' to maintain an oil-tightLhousing: about the crankshaft and associated operating members. The casting H is characterized by a cover-engaging margin 42, shown as disposed at a slight angle to the vertical, and a lower periphery or margin 43 at a right angle to the edge 42, and disposed at a slight angle to the horizontal. The cover I 3 may be secured in mating relation with the margin 42 as by cap screws or the like 44, and held in assembly adjacent the reservoir portion of the case, as by screws 45.

For the purpose herein described, the margin 43 of the cover will lie in the plane of and adjacent to the surface 25 (Fig. 6), forwardly of the main bearings. The surface 25 is, however, not

continued rearwardly of the main bearings in the example shown.

Proceeding now to a more detailed description of the detachable cover 43, this member is by preference and as shown, of dome-shaped construction, the lower or base engaging margin within the cover for a purposehereinafter more clearly appearing. Preferably at diametrically I opposite p'oints,-the lip 48 is notched as at 50 (Figs. 1 and 7), providing for drainage of oil therethrough-from the trough 49 into oil-receiv- .ing pockets 5! in the upper bearing halves. Each "of the pockets 5| is provided with a vertical 'drainopening 52 directed downwardly through the upper bearing portion to the shaft 20.

. Since theupper bearing halves are subject tovertical adjustment, within limits, for the purpose of taking upwear, and since the cover 13 is fixed in'p-osition as by engagement of the seat- Iingsurfaces25 by, the margin 42, it is desirable tov provide a gasket or sealing material such as felt or the like, indicated at 53, between the case -l 3 and. the upper bearing halves. This gasket material is, in the present example, disposed along andparried within the groove 36, in the trans- 1 verse rib member 34, (Fig. 4) Due to the compressibility of the gasket material, an oil-tight H joint exists between the cover l3 and the bear i nghalf, irrespective oi any ordinary bearing adjustments or take-up;

In the event, howeverpsome of the splashed oil shouldseep outwardly between the cover and bearing halves, and beyond the gasket 53, such oil is entrapped in an oil drain groove 54 disposed over each bearing "half, between the ribs .34 and 35. 4 Any oil which thus Iseeps past the gasktand findsits way intotl'ie groove or duct 54 is directed downthe sides'of the bearing half,

fth'enc'e into the'vertical oil return groove 28 (Fig.

6), down the slopingfportion thereof and into .the'uhde'rcut cavity 29; at each side of the bearing, whence it'is distributed'along the journalled ""portionjof shaft 20 for lubrication thereof. Details of the arrangement of gaskets, 53, oil pockets andducts SI and 54*and the oil return passage 52, will even more clearly appear from the en-"" larged details of Fig. 3.

In operation, a level of oil is kept within the reservoir portion l4, to such a height that it is agitated for spray lubrication purposes, by the crankthrow and rod end dippingtherein. Theoil and oil spray is thus carried upwardly to the interior surface of cover I3; the oil flows thence by gravity along the innersurface of the cover *to collect in the peripheral trough 49, proceeding thencaas above described, through the notchi5ll,

2 "and in-to the main bearing. Distribuappropriately disposed oil-distributing grooves 1-55 any excess 6f oil finding "its wayoutwardly "along the shaft, to be "picked up by collecting ring'-"38, thrown into'ithe annular passage30 and thence returned through the drain channels -39,

Gomple-te -andcopious"lubrication of the-bearings will obviously result fromtheforegoing arrangement, which serves, besides an oil-directing function, to prevent escape of any oil to the outside of the case, thus keeping. the exterior of the engine dry and clean at all times, preventing waste of lubrication, and. otherwise attaining the several objects set forth above.

It is, of course, to be understood that thepresent detailed description of parts and the accompanying drawings are presented only as pertaining to a preferred, exemplary embodiment of,

the invention, and that numerous changes may be made in the constructionas described, without departing from the intended spirit and scope of the invention asdeflned by the claims hereto appended. i

I claim as my invention:

1. In an engine, a casing including an oil reservoir in its lower portion, mechanism disposed to be oiled in part by splash, from a body of oil in the reservoir, a splash-oil-receiving closure having its margin seated upon the upper portion of I the reservoir, an oil collecting channel in said closure, an oil-leakage trough covered by the margin of said closure, and oil passages from said channel and leakage trough, to parts of said mechanism.

2. In an engine, a casing including a lower oil containing portion, mechanism disposed therein to agitate a body of oil in said casing, a splash and gravity oil-circulating means including a splash-deflecting cover disposed in splash-receiving relation to the mechanism within the casing, a splash-oil-receiving channel disposed along the internal periphery of the cover, and another on the lower case portion beneath the cover, a gasket element between the cover and lower case portion, and located adjacent to and inwardly of the last named channel, conduits disposed for gravity flow of oil from said channels to parts of said mechanism, and oil ducts for returning oil from the gravity-lubricated parts of the mechanism to the lower portion of said casing.

3. A crankcase construction for engines employing splash lubrication, including an oil reservoir forming the lower portion of the case, a splash-receiving closure seated upon the reservoir and constituting the upper portion of the case, an oil channel formedperipherally within said closure, engine bearings, ducts from said channel to said bearings, a leakage channel eX- tending along the seat for said closure, means for returning oil from the leakage channel to the bearings, and oil drains from said bearings having their discharge termini in the lower portion of the case.

4. In an engine crankcase, a lower case section, a bearing portion formed therein and having stepped lateral surfaces, a detachablecompanion bearing'portion having similarly stepped surfaces, the stepped surfaces of thebearing portions interengaging in assembly, toprevent displacement of the portions, an upper case-closure section seated in part upon the detachable bearing portion, means securing the bearing portions tions formed on the detachable bearing lp'ortion,

bearing, for med by undercut 'porti'o'ns' of "said steppedssurfaces; I x

5. In-an eng'ine crankcase; a lower casepdrti'on forming lower bearing halves "for a crankshaft, stepped surfaces laterally adjacent: the lowerbearing halves, an upper case-closure portion; a

seat'forsaid closure portiondisposed above the lower bearing halves, companion or upper beare ments, and directed into the lower bearing halves.

6. In a crankcase structure, a lower case portion forming lower bearing elements, upperbearing elements interengaging the lower bearing elements, paired transverse ribs on the upper bearing elements, a recess along the outersurface of one of said ribs, a compressible sealing element occupying the recess, an oil channel between said ribs and directed into the bearing formed by said elements, and a coverfor the lower case portion, having a flange seated on the compressible element, and overlying and serving as a cover for said'oil channel.

'7. In a crankcase structure for engine, a lower case portion forming lower bearing elements, upper bearing elements detachably secured to the lower bearing elements, an oil recess or cavity on each of the upper bearing elements, a cover for the lower case portion, overlying the bearing elements and arranged for deflecting splash oil from within the case into said recesses, additional oil recesses formed on the upper bearing elements outwardly of the first said recesses, cover-sealing members on the'upper bearing elements between the oil recesses, and a passage from each of said recesses, to the bearing surfaces of said elements.

:8. In an engine crankcase, an oil-collecting dome disposed within the path of splash oil from mechanism within the case, an inwardly extending peripheral oil'trough formed in said dome, bearing elements carried by the case, oil pockets formed in the bearing elements, certain of the pockets being arranged to be supplied from the oil trough in the dome, said dome constituting a cover for the case and each of said trough and pockets, means for conducting oil, by gravity,

from said trough and pockets to mechanism other 9. In an engine crankcase, in combination, a I

concave closure member having a flange seated in substantially fluid tight relation on the case,

a sealing member cooperating with the flange, an internally projecting marginal trough carried by the flange, a leakage trough. on the case structure laterally of the sealing member, each of said troughs having an opening therein for j discharge of oilfrom the troughs, and conduits fordirecting such oil to engine bearings and like parts to, be lubricated.

10. In an engine crankcase, two detachably connected companion enclosure portions, a body of oil in one vof said portions for splash lubricajtiOIiOf parts within thecase, a splashed-oil-collecting channel carried by the other portion, .a sealing member between the portions, andtan oilcollecting and -drainage channel between said portions. and disposedoutwardly of saidv sealing member,

,, v 11. In a crankcase for a splash-lubricated enp gine,"a lower oil-containing case portion, an upper hollowed case portion detachably secured second oil-collecting trough disposed outwardly of the gasket, substantially between said portions, and passages from the second named trough, communicating with the interior of the 10 lower case portion.

' FRANKLIN G.'HOBART. 

